Substantive due process

A doctrine holding that the 5th and 14th Amendments require all governmental intrusions into fundamental rights and liberties be fair and reasonable and in furtherance of a legitimate governmental interest. The U.S. Supreme Court during the middle of the 20th Century used substantive due process to give added force to the 4th, 5th and 6th Amendments of the U.S. Constitution by constraining certain actions by law enforcement, prosecutors, and judges.